He made epigraphy his particular theme, and at the age of twenty-three became a professor of rhetoric at the University of Angoulême, where he lived and worked for ten years without further ambition.

In 1861 he was made professor of Latin oratory at the Collège de France, and he became an active contributor to the Revue des deux mondes.

In L'Opposition sous les Césars (1875) he drew a remarkable picture of the political decadence of Rome under the early successors of Augustus.

By this time Boissier had drawn to himself the universal respect of scholars and men of letters, and on the death of HJG Patin, the author of Études sur les tragiques grecs, in 1876, he was elected a member of the Académie française, of which he was appointed perpetual secretary in 1895.

Though he devoted himself mainly to his great theme, the reconstruction of the elements of Roman society, he also wrote monographs on Madame de Sévigné (1887) and Saint-Simon (1892).